Field of the Invention
The invention relates to an inking unit for rotary printing presses, with a cleaning device for cleaning inking rollers including a distributor roller disposed alongside the inking rollers for supplying therethrough a given quantity of cleaning liquid, a plurality of outlet elbows via which the cleaning liquid is applicable onto the inking rollers, and a drip pan disposed beneath the outlet elbows.
In modern high-speed rotary printing presses, the cleaning of inking rollers is performed automatically and program-controlled, so that the cleaning process takes place in the shortest possible time. The cleaning cycles are performed manually or program-controlled, so that for a multicolor press only brief interruptions in the printing process are necessary. Inasmuch as a multiplicity of outlet elbows are provided for supplying the cleaning liquid, in the case of a multicolor printing press, the danger of subsequent dripping arises, which would lead to disruptions. A drip pan under the outlet elbows reliably prevents penetration by cleaning liquid into the inking unit during the printing process, and consequent disruptions. When automatically operating the rotary printing press, and when using cleaning media having low vaporization, small quantities of dripped-off cleaning liquid accumulate in the drip pans and must be removed.
A device for cleaning ink-feeding rollers has become known heretofore from the published German Patent Document DE 31 28 928 C2, wherein an aerating tube is assigned to a distributor tube in order to achieve a no-load operation of the distributor tube. Subsequent dripping of the cleaning liquid is thereby supposed to be prevented.
In this heretofore known device, the distributor tube must be filled with cleaning liquid for each cleaning operation, which requires a given amount of time. The required quantity of cleaning liquid is consequently determinable only with great difficulty. Moreover, drops of cleaning liquid may remain suspended both on the supply tubes and on the aerating tubes, and can penetrate into the inking unit at an indeterminate time and can cause disruptions therein.
In a further construction in accordance with German Patent 197 112 545, a device for emptying a drip pan has been disclosed which requires a construction expenditure which must match or be adjusted to the respective press configuration.